Definition - What does Lenticel mean?
Lenticels are the pores of outer plant tissue that provide a direct exchange of gases between internal plant tissues and the atmosphere. Bark is normally impermeable and the exchange or release of internal gases would be impossible without the plant's lenticels.
Lenticels are also present on fruit and can be used to determine the ripeness of apples, pears, and other fruits. Light lenticels will darken as the fruit reaches the final stages of ripening and this colors the fruit.
MaximumYield explains Lenticel
For a plant to survive there must be an exchange of gases with the atmosphere. Lenticels provide this mechanism.
However, lenticels can sometimes expose a plant to a fungal infection that enters the plant through these pores. There is also a condition known as lenticel breakdown that forms pits on the surface of harvested fruit.
Lenticels are most common in older varieties of apples as the gala, granny smith, or golden delicious. It can be avoided by spraying the fruit with lipophilic coatings just prior to harvesting.